Lubrication pump



May l2, 1942. 1 RUSSELL LUBRICATION PUMP 2 Sheets-Sheet l` Filed Jan, 22, 1940 INVETR ATToNr-:YS

May 12, 1942- J. RUSSELL 2,282,429l

LUBRICATION PUMP Filed Jan. 22, 1940 A Sheets-Sheet 2 IlII www.,

Patente-d May 12, 1942 LUBRICATION PUMP John Russell, Danbury, Conn., vassigner to Pressurelube, Inc., Dover, Del., a corporation of Delaware Application January 2'2, 1940, serial No. 315,054

(C1. 10s-16s) 5 Claims.

The present invention relates to lubrication apparatus and more particularly to a novel and improved double-acting high-pressure grease Dump.

Objects and advantages of the invention will e be set forth in part hereinafter and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims,

The invention consists in the novel parts, constructions, arrangements, combinations and improvements herein shown and described.

The accompanying drawings, referred to herein and constituting a part hereof, illustrate one embodiment of the invention, and together with the description, serve to explain the principles of the invention.

Of the drawings:

Fig. l is a horizontal sectional View of a typical and illustrative pump in accordance with the present invention;

Fig. 2 is a top plan View of the pump shown in Fig. l; and

Fig. 3 is a horizontal sectional view taken on the line 3 3 of Fig. 2.

The present invention has for its object the provision of a novel and improved double-acting high-pressure grease pump which can deliver grease at high pressures with` a relatively small load on the actuating motor. A further object of the invention is the provision of an improved high-pressure grease pump in which means are provided for positively delivering grease to the high-pressure pump chamber so as to insure a full charge of grease being delivered on each re ciprocation of the pump plunger. The invention also provides a high-pressure grease pump having selectively operable means for preventing delivery of grease and relieving the motor of most of its load while the pump continues to reciprocate. Still another object of the invention is the provision of a pump for delivering grease at extremely high pressures which is particularly adapted for operation by means of a storage battery powered motor.

In accordance with the present embodiment of the invention, the pump comprises a pair of reciprocatory pump plungers operating together and of diierent cross-sectional area. The larger plunger is in direct communication with the grease supply, and is adapted to receive a charge of grease from the supply by the suction developed during the operation ofthe pump, and f' this charge of grease is delivered through a check valve into the high pressure part of the pump which includes the plunger of smaller cross-sectional area,kthe bore and stroke of the larger pump being so proportioned with respect to the bore and stroke of the smaller plunger, that on the pressure stroke of the larger plunger, the quantity of grease delivered to the smaller plunger is sucient to fill the smaller pump chamber. On the reverse stroke of the two pump plungers, the check Valve between the two plungers is closed, the smaller plunger compresses the charge of grease and delivers it at an extremely high pressure through a second check valve and into a chamber communicating with the hose or other conduit of the lubricating apparatus, and on the same stroke the larger plunger creates suction so as to cause its chamber to be filled with grease as it approaches the end of the reverse stroke. Means are also provided for holding open the check valve between the first and second pumps so that, if desired, the pump may be allowed to continue reciprocation,

and the grease flows idly back and forth through the check valve from one pump to the other with noV additional grease being delivered to or from the pump.

While the invention is of some general application in connection with highpressure lubrication equipment, it is particularly useful in connection with storage battery power greasing equipment such as that shown in the patent to Brown No. 1,956,144 inasmuch as the load on the pump-actuatingmotor is distributed throughout approxi` mately three fourths of the time of operation, whereas in a single acting pump such as that shown in the patent to Brown, the load occurs almost entirely during one fourth of the time of operation. In other words, the maximum demand on the battery is greatly reduced, resulting not only in exceedingly longer battery lifey but also permitting the use of'a'smaller size of motor which is not subjected to excessive overloads, and this reduced maximum demand also permits a greater amount of grease to be delivered' at a given pressure for a single charge of the battery.

It will be understood that'the foregoing genera-l description and thel following detailed description as well are exemplary and explanatory of the invention but are not restrictive thereof.

Referring now in detail to the illustrative embodiment of the invention shown in the accompanying drawings there is provided a grease supply chamber i6 for the pump, said chamber being cylindrical and having a flanged top Il for attachment to the outlet of a grease container 9 from which the grease is preferably fed under pressure into the cylinder I0. 'I'he flange II is suitably provided with a plurality of bolt holes I2 for attachment to the grease container. Grease cylinder I is formed as a projection of a main cross-shaped casting which houses the pump chambers and plungers and the grease expelling conduit and valves and the control means for said valves. Referring first to the doubleacting pump mechanism, same comprises a relatively large-diameter plunger I on the right hand side of the main housing (Fig. 1) which plunger communicates with and passes through the grease supply chamber I0. The opposite sidev or branch of the main housing receives the second or small-diameter pump plunger I6 which is in line with and opposed in stroke direction to the larger plunger I5. The two plungers are connected to move together by a yoke mechanism comprising on the right side a cross head I1 centrally attached to the outer end of plunger I5 and connected at one end to the yoke rod I8 and the other to the yoke rod I9. A similar, centrally threaded cross head 20 is threaded onto the protruding end of the small diameter plunger I6 and the ends of said cross head are attached to the rods I8 and I9 as shown. Reciprocating movement is imparted to the pump yoke and its plunger by a reciprocating shaft 2l which is suitably threaded to a hollow nut 22, the inner end of which fits about the shank of the nut 23, on the protruding threaded end of the plunger I6. Reciprocatory movement may be imparted to the drive shaft by any suitable prime mover, but in the preferred use of the invention a storage battery driven motor is employed, the characteristics of the pump of my invention rendering it peculiarly advantageous for operation from a storage battery.

Referring now to the housing and action of the large diameter pump, the plunger I5 is slidably mounted in a close fitting cylinder 25. Said Y cylinder is fixed in the main casting and bridges across the center of the grease chamber I6, the inner end of the cylinder being reduced at 26 to abut against one wall of the grease chamber and being provided there with a grease sealing gasket 21. The opposite end of the cylinder 25 is tightly fitted in a hollow projection 28 of the main housing and said projection is threaded near its outer end to receive a sealing nut .29. Said nut is hollow to chamber the reciprocating plunger I5 and is provided with a suitable sealing gasket 39 and packing 3I. The cylinder 25 communicates with the grease chamber. Ill by means of ports formed by a centrally-disposed horizontal conduit 35 and by an intersecting vertical conduit 36. v

Referring now to the generally similar mounting for the small diameter plunger I6, same comprises a close tting cylindrical sleeve 4I! tightly fitted and sealed within a cylindrical chamber 4I 42 of the main housing. The inner end of sleeve 40 is chambered at 44 to provide a grease well about the inner end of the plunger I6 and a free space 43 is provided between the end of sleeve 40 and the inner end of chamber 4I. The chamber 4I is enlarged at its outer end and threaded at 45 to receive a sealing'nut 46 which has a sealing gasket 41 and packing 48 and is hollow to fit closely about the plunger I6.

Referring now to the common outlet for grease ejected by the pump plungers I5 and I6, same formed in the left-hand projection y comprises a cylindrical chamber 59 bored centrally through the branch 5I of the main housing and extending to the center of the housing where it is arranged to communicate with both pumps. The outer end of grease chamber 50 is in communication with a grease hose or conduit 52 for ultimate delivery of the grease. Said conduit 52 is threaded into a hollow nut 53 which in turn is threaded into the end 54 of the chamber 50. At its innermost end grease chamber 5I] is provided with a lateral conduit 55 which communicates with the space 56 between the inner end of pump cylinder 25 and the main housing, thereby affording passage of grease from the large pump I5 to the chamber 50. Similarly at a lower point a lateral conduit 51 communicates with the space 43 at the inner end of pump I6.

The invention provides means for controlling the passage of grease from pump I5 to the pump I6 whereby the grease forced by the pump I5 will be caused to enter the grease chambers 42 and 43 of pump I6, and thence upon the stroke of pump I6 to pass again into the chamber 50 at a lower point for expulsion into conduit 52. As shown, a ball check valve is provided in the chamber 56 between the grease conduit 55 and the grease conduit 51, said valve comprising the ball 6I] seated in the hollow seat 6I which is suitably threaded into the wall of chamber 50 between the two lateral conduits 55 and 51. The ball is forced against its seat by a helical spring 62.

Additional valve check means are provided for affording passage of grease into the conduit 52 from the upper part of the chamber 5I) only when a suitable high pressure is imparted to the grease. As shown, an intermediate hollow valve seat 65 is threaded into the walls of chamber 50 and is shaped to receive on one face a valve ball 66 which is forced against its seat by helical spring 61. the inner face of the sealing nut 53, while the helical spring 62 is similarly xed to the opposite face of the valve seat collar 65.

Referring now to the operation of the elements of the pump above described, movement of the plunger I5 to the right, as in the solid line position (as in Fig. 1) causes a suction to be created in the cylinder 25 which draws grease from chamber I0 through the ports 35 and 36 as they are cleared by the passing of the end of the plungei'. The cylinder 25 is thus lledwith a load of grease. Upon the return stroke of plunger I5 that load of grease is forced out of space 56 through conduit 55 and into the upper part of chamber 50. The increasing pressure caused by movement of the plunger forces the ball 60 from its seat and allows grease to travel along said chamber 50. The closed cylinder displacement of the large plunger I5 is equal to that of the smaller plunger I6. That is, the closed space beyond the ports 35 and 36 is of a volume equal to that of the space occupied by the plunger I6 at the end of its stroke. Consequently, the grease delivered by the pressure stroke of plunger I5 all passes into the space cleared by the retreat of plunger I6, thereby loading that portion of the pump with grease. The retreating movement of plunger I6 causes a partial vacuum in those spaces which facilitates the entrance of grease. Upon the return stroke plunger I6 forces its load of grease into the lower part of chamber 56 through valve 66 and intov conduit 52 thereby providing delivery of grease during the The opposite end of spring 61 abutsfull return stroke of the pump. Thus the pump operates under load during three-quarters or 270 of its cycle, that is, upon the full return stroke of plunger I6 and upon the second half of the said stroke of plunger l5. The distribution of the load with respect to the motor and storage battery is therefore fairly uniform.

The amount of grease delivered by the large plunger to the small plunger may be varied by varying the position of the large piston l axially with respect to the yoke bar Il. This may be done in practice by an adjustable threaded connection (not shown) between the end of the plunger and the yoke bar to permit various settings of the plunger axially with respect to its cylinder.

The invention further comprises means for selectively preventing delivery of the grease into the conduit 52 while continuing the running of the pumps, thus permitting an idling operation relieving the motor of most of its load. For this purpose means are provided for selectively unseating the valve ball 50, thereby to permit free passage of grease between the two pumps. As shown, a slidable plunger 'ID is mounted in a cylindrical chamber 'H in the branch 12 of the main housing. The inner end of said plunger is reduced in cross-section and extends into the inner part of chamber 50 to normally lie a slight distance away from the ball 60. Plunger 'l0 is normally held in said retracted position by a helical spring I3 housed in a cylinder 'H and surrounding the plunger. The outer end of said spring abuts on collar ld, secured on plunger l0, and the lower end abuts a collar l5. A suitable seal 'lo is provided between the collar 'l5 and the inner reduced end 1l of the cylinder 7l. A knurled nut '18 may be fixed to the outer end of the plunger 70. It will be clear that by forcing the plunger inwardly the ball 60 will be unseated and now of grease to the conduit 52 will be prevented because of lack of pressure to unseat the valve ball 63 upon any stroke of the pump. Thus the pump plunger can idle back and forth at relatively low power consumption. Also, if desired, the delivery of grease by the pump, cooperating for example with the grease gun itself, may be directly controlled by operation of the plunger 1U.

The invention in its broader aspects is not limited to the specific mechanism shown and described but departures may be made therefrom within the scope of the accompanying claims without departing from the principles of the invention and without sacrificing its chief advantages.

What I claim is:

1. A grease pump including in combination a supply of grease, a grease outlet, a pair of reciprocable plungers, one of said plungers having means for drawing grease from said supply and means for feeding same to the cylinder of the other plunger, means for delivering the grease forced from said cylinder by the second plunger to the outlet, valve means for normally preventing passage of grease from the cylinder of the second plunger to the cylinder of the first plunger, and selectively operable means for rendering said valve means ineffective thereby to permit an idling interchange of grease between said plunger cylinders.

2. A grease pump including in combination a supply of grease, a grease outlet, a pump plunger and cylinder for forcing grease from said supply to said outlet, a second plunger and cylinder, means for delivering grease drawn from the supply by said first plunger to be pumped by said second plunger, means for delivering grease from said second plunger to the outlet and selectively operable means for permitting the return movement of grease from the second plunger cylinder to the first plunger cylinder to relieve the pressure on said grease.

3. In a grease pump, a pair of plungers and cylinders of different diameters reciprocable together, a communicating space between said plungers, a grease outlet communicating with said space, means for supplying grease to the larger plunger, and means in said space controlling communication between the plungers, said means being a one-way valve displaceable by pressure from the larger plunger and means for selectively displacing said valve predetermined amounts to permit return of grease from the smaller plunger to the larger.

4. A grease pump including in combination a supply of grease, a grease outlet, a pair of reciprocable plungers and cylinders of different diameters, the larger of said plungers having means for drawing grease from said supply and means for feeding same to the cylinder of the smaller plunger, means for delivering the grease forced from said cylinder by the smaller plunger to the outlet, valve means for normally preventing passage of grease from the cylinder of the smaller plunger to the cylinder of the larger plunger, and selectively operable means for rendering said valve means ineffective thereby to permit an idling interchange of grease between said plunger cylinders, said selectively operable means being variably positionable to control the amount of said idling and thereby regulate delivery of grease from the pump.

5. A grease pump including in combination a supply of grease, a grease outlet, a pump plunger for forcing grease from said supply to said outlet, a second plunger, means for delivering grease drawn from the supply by said first plunger to be pumped by said second plunger, means for delivering from said second plunger to the outlet, each of said plungers having cylinders, and means for controlling the amount of grease delivered to said outlet comprising variably positionable means for permitting return of a selected quantity of grease to the rst plunger.

JOHN RUSSELL. 

